Firing head assembly for fuel burners



the eiiiciency of the burner apparatus.

Patented Dec. 22, 1953 UNITED. ysTATi-:s PATENT OFFICE:

RNERS Ralph De Lancey, Yalesville, Conn., assignor f to The Miller Company, Meriden, Conn., a co1"- ":porationof Connecticut Application-A'pril 14, 1951, Serial No. 221,041

. i3 l@ This invention relates toa Afiring head assembly for fuelburncrs'and,more particularly to a firing head for gun burners offthetype in'Which the fuel is pumped under pressuretoa nozzle and there atomized inthe form of a mist or spray and mixed with a blast` of [air supplied byl a blower, theV resulting fuel-air mixture being discharged into the combustionvc'hamber'of the furnace where itis burned. Dueto imperfections in the orifice of the fueln'ozzle, the pattern of Ydispersed or -atomized fuel is often irregular, that is, greater amounts of fuel are discharged in some directions than in others.' These imperfections may be occasioned b'y'slght mechanical inaccuracies inherent in the methodjof'ma'nufacturing .the nozzle, or they may arise from the Vformation of a slight, tenacious l'm'depos'ited in the orifice during use of the burner. In 'either case, such imperfections cause the name "produced, by the.

burner to have a tail or tails which jut out y:from the main body ofthe name. 'V'Ifhis leads to improper combustion and consequently lowers It is a purpose 'of the present invention to provide a firing head construction which will permit adjustment to be made whereby the effect of these irregularities may be largely, if not wholly, compensated for. 4lurthermo're,.'by means of l the 8 Claims. (Cl. 158-76) novel firing head construction. hereinafter'del scribed, the aforesaid compensation for llame irregularities xnayfbe.v accomplished while the burner is in actual operation soth'at the effect of theV adjustment made is immediately observable.

Heretoffore it. has, been necessaryv where name pattern irregularities ofthe type here in. question haveoccurred vto shut 01T, the burner equipment and to disassemble it sufli'ciently to vpermitwithdrawal of the firing head assembly from the air blast tube'or' duct so ,that the nozzle can be y cleaned or otherwise adjusted or replaced. The equipment must then of course' be reassembled and started up again in order to .determine ,Whether the difficulty has -been cured. It will be obvious lfr'om'the foregoingthatv it is practically impossible for a service manfto determine in advance whether or not he is ,accomplishing the desired result, and he must therefore resort to repeated disassembly, .reassemblyl and operation of the equipment. It is not at all an uncommon experience in actual practice to flndthat considerably more than half of any averagegroup of nozzles picked at random, all ofthe same make and model, will produce a tail or tails in the flame .when installed in a burner. explained above,

these tails are caused by very slight, sometimes imperceptible, imperfections in the nozzle orifice which cause or at least allow the discharge of an excess amount of oil in a particular direction, with the result that not all of the oil in that tail is properly mixed with air and burned. Where these tails extend downwardly toward the bottom of the combustionjchamber, they are deflected by the walls of the chamber and lare curled back toward the main body of the flame where further mixingl of the excess fuel with additional air supplied by the blower can then occur. Under such circumstances combustionis more nearly complete and the imperfections are of little importance. Where, however, the tail is directed upwardly towards the top or sides ofthe combustion 'ch-amber, there islittle or no opportunity for 4'matter be rotatively adjusted with respect to the rest of the iiringhead assembly, little or no control of the direction can be accomplished in which a. tail, if present on the flame, extends in the combustion chamber. In most prior burners, therefore, it is whollya matter of -chance in what directionthe tail shall extend and the solution to the problem hasbeen to disassemble the burner and replace the nozzle with a different one until one is found which gives a satisfactory llame pattern. And even in the one or two instances in which attempt has been made in the prior art to allow for` rotative adjustment, only limited adjustmentrhas been achieved, and this by rotating the entire ringhead assembly. Not'only does this require that the ignition electrodes be mounted independentlt7 of kthe rest of the ring head (commercial codes require these to be horizontally opposed) but it also introduces further problems of'disturbing the air distribution because of rotation of the 'deflector vanes. l

With the use of vthe firing head'here disclosed, the flame producedbytheburner may be bodily turned about its axis4 any desired amount while the burner is operating, in order'to position a tail at or near the floor of the combustion chamber, and this is accomplished without in any way disturbing the ignition electrodes or air deflector vanes.

A specific embodiment of the invention is illustrated in the accompanying drawings and described in detail hereinafter. The drawing and description are, of course, merely illustrative and various modifications. can be made aswill. be apparent.

In the drawings Fig. l is a diagrammatic illustration in side elevation of `a burner ring into a combustion chamber, the flame produced haring a. typically Y irregular pattern;

Fig. 2 is an illustration of) .the Same burner shown in Fig. 1, adjustment having-beenmade as provided by the present disclosure to compensate for the irregular flame pattern;

Fig. 3 is a side elevational-view,^'partly in vsection and partly broken away, of a gun burner. air duct having a firing head assembly constructed in accordance with the invention; and

Fig. 1 is a fragmentary viewl in plan looking frombelow, f the forwardportionlofthe firing head assembly Ashown in Fig. 3.

Fig. l illustrates a typical case in which a burner Iii is employed in conjunction with a furnace having walls Il defining a combustion chamber I2. In this instance the flame produced by. the burner assumes an irregularpatternfthe main body of the name being indicated at I3 and having a tail I4 which .extends upwardly toward the top of vthe combustion chamber l2. Under these conditions, there `is some waste of fuel because, an appreciable amount of the potentially combustible volatile products present in the tail I4 passes out through the flue of the` furnace ,in an unburned oronly partially burned condition. The flame pattern here illustrated is, of course, the extreme case, in that the tail isdirected sub stantially straight up in the combustionchamber, buta similar lossoccurs whenever the tail, 'if present, is located at any point other than Substantially at ornear the bottom of the main body I3 of the iiame. The idealsituation, of course, is one in which the flame pattern is `perfectly symmetrical in all directionsbut as explained above this is not obtained .in actual practice in most cases.

Fig. 2, von. the other hand, shows whatoccurs when the tail I4 is positioned onthe under side .f

of the main body ofthe ame. In this instance, the tail strikes ythe floor, or the walls adjacent the floor, `of the furnace and is directed back toward the 4main .body I3 of the flame. `Where this occurs, theunburned volatile products carried r by the tail I4 are mixed with additional air supe plied by the burner I0 and are burned, inthe main body of the burner flame. `Not only does this increase the eiciency of the burner by more completely burning the fuel, but it'v also reduces the formation of soot which would-otherwise be deposited upon the heat exchange surfaces of the furnace,` thereby lowering 'the heat transfer' elliciency of those surfaces.

A ring head assembly is shown in Figs.' 3 and 4 which will'permit a serviceman to turn the body of the dame about its axis as it issues from the `burner blast tube.v :In Fig. 3,: the-portionslof burner IB shown include the -rear of the blower housing I5, the forward part of the blast tube or duct I6 and the enclosed ring head assemblyindicated generallyat IT. Thelatter extends from a point adjacent the discharge. end, of duct I6 back through the rearwall Ia of the blower housing. Firinghead assembly I 'I includes a central fuel pipe or conduit I8 which is carried within a loosely fitting sleeve I9 which, as will more fully hereinafter appear, is suitably held against turning movement about its axis. The conduit is threaded at its rear or fuel-receiving end, and an internally and externally threaded nipple isscrewed on to that end-of ltheconduit. Nipple 20 receivesa Agland nut 2Iswhich vserves to connect the flared end of the fuel supply pipe 22 to the fuel conduit I8. The forward end of conduit I8 is also threaded and is received within a nozzle `iaolalzvter23`uhaving a passage 24 which extends =axially through the adapter. At its forward end,

the.adapterucarressa spray nozzle 25 provided .withrthesusual':filter ZIB through which the fuel O iLpiSsesiiILgDnga-to the very fine discharge oriflee of the nozzle. The firing head'assembly is -alsof-providedatrits forward end, adjacent the nozzle, lwith stationary air deflector or swirler vanes 2'I which are used to impart a turbulence Vto the arasit isemtted from the blast tube in order td effect Aa` bltelrmixing of air with the atomized fuelllnlthis instancejthe deector varies 2].arel formed by radially slitting an annular disc orflange' forming askirt at. one end of a tubular shell orhllbi 28 and .then bending the blademembers thus' formed out of their, original plane into non-coincident, substantially parallel planes. VThe overall diameter ofthe air deiiector corresponds tothe internal vdiameter of duct I G so "that ithe tips, of blades21 .contact the duct circumferentially and thus center 'the deliector in the duct. rShell 28.is made'fast to a second tubular memberZBTittingItherewithin and having, at its rear end smalllugs 3B which serve to hold the, adapter23 and nozzle25 in spaced coaxial relation to member 29. As seen in Fig. 3, the air deector justzdescribed is provided with a bridge member 3| secured Vtd theunder side of shell 23 at its rear end. '#Brldge 3I..eXtends rearwardly in cantileyerfashion 'from .the vdeflector assembly and is connected to ayoke 32 by means of screw 33 to supportthe yoke in 'the'duct I6. Yoke 32 is apertured centrally toA receive the forward end of sleeve"I9, as wellas'to allow fuel conduit I8 Yto pass therethrough. *A setscrewBli located in the same hole as screw'33 serves to lock the yoke 32L to the forward end'Y of sleeve I9, but conduit I8 is left free` for rotation .within theV sleeve. In this .manner conduit I8, nozzle adapter 23l and nozzle 25 are free for rotational movement with- ,in'sleeve I9. independently of the air defiector assembly, and atthe sametirne are supported withinthe blastvtube I6 by the A'lat-ter-means `Yoke `32 also carries therear ends ofgthecignition electrodes, 31 and'theirporcelain-'insulators 38 Yto dispose'them horizontally; on-opposite sides of the nozzle andanozzle adapterin conventional manner,'the electro-des and insulators being supported adjacent their forwardendsby the deflector in passing 'through'holesiprovided Vtherein for that purpose.

iAtthe'fuel-receiving end of;v conduit -I 8, a collar or, bushing 35 is welded :or otherwise lsuitably, securedttosleeve I9. *This Icollar fits closely'vvithin an aperture 36' pro-videdin-theI rearwall I 5a of the blowerchousingso that A'the vfiring head assemblyis thussupportedadjacent its-fuel-receiving'end -by lthe-wall off-the: blower housing. As here vshown;'collar *35i* has aiA locating key orlug 35a secured-to it'whichts intofa corresponding slot- `or-keywayj `|151 opening 'intoaperture 3B in wall Ilia. Thisserves to-angularly=position the air derlector and 'electrodeassembly of the firing head-within :duct'fl 6 and-=serves` also' to prevent turning of thisy 'assemblywith rotativef angular adjustment of the nozzle 25 now to be described.

In'or'der to rotatively adjust' themnozz'le'so; as -toput'any tail on the" llame produced thereby a't or near the bottom 'ofthe'main'b'ody of the llame, it is merelyA necessary in the construction here shown topartially uncouple gland `nut2l from nipplev 20 in 'order' to permity doing this. Even though the'burneris in operation andful is being supplied to the fuell pipe 22 under con- 'siderable pressure, sufficient uncoupling `can be vaccomplished without letting oil leak otat this point to permit the conical seat provided by the flared end of tube 22 to tuinonv the mating surface of the nipple With the coupling "connection thurslloosened, proper application fof a wrench to the head of nipple V 20 whereby" to turn the whole'jlunit, l consisting fof saidr nipple, 4 fuel conduit lI8,adapter 23 and"nozzl`er 25,V through the necessaryy angular distance to accomplish-the vdesired adjustment.. Since, in this-'adjusting movement, "the fuel conduit turns within stationarylsleeveflil' while the nozzle adapter turns within vmember 29 lvvhichf is Yfastlwithshell 28, said adjusting movementcauses' no rotation'o'r turning movementvof the airdeflectorassembly and the electrodes carried thereby.' "Furthermore, no strain or twisting is imparted to the fuel line 22 since the conical tip of nipple 20 simply turns within the viiaredmating nend of pipe 22. The service 'man' can thus adjust the angular position of the nozzle until the desi-red positioning of the flame is obtained. When this has been done,the coupling connectionu can againbe tightenedup by turning gland nut 2l. Theconstruction sho n thus permits angular rotative adjustmentsv Y Y nozzle withoutpin any mannerA disturbing the air deflector meansand; equally as lirriportant without disturbingthe ignition :electrodes hereshown, sleeve `Alsextends thefullrdistance between the shoulders of nipple 20 and the rear end of the nozzle adapter 23. This construction thus prevents any axial shifting of the nozzle with respect to the position of the delector vanes 21, which is desirable for many applications. If desired, of course, the construction can be such that axial adjustment can be made both in the positioning of the entire ring head assembly with respect to the mouth 39 of the blast tube I6 and also in the positioning of the nozzle with respect to the air deflector vanes 21. Similarly, while it is convenient from a manufacturing standpoint to have sleeve I9 in bearing contact with conduit I3 throughout the length of the sleeve, this is not essential as will be readily appreciated.

The principles of the present invention are applicable equally to burners producing a substantially solid body of ame suchas that diagrammatically illustrated in Figs. 1 and 2, as well as to burners producing a hollow conical ame. Both types are subject to the presence of unwanted tails on the flame.

The term spraynozzle assembly as used herein refers not only to the terminal member having the fine orce from which the oil spray actually emerges at the mouth of the blast tube, but it also includes an adapter member, where one is present, connecting the terminal nozzle member to the fuel conduit.

What is claimed is:

1. A firing head assembly for fuel burners of the gun type having a tubular air blast duct adapted for `connection to a blower, which assembly is adapted and arranged to be positioned agees-sas in`s`aid duct and Iwhich 'oomprises a fuel" conduit liavingfuel-'receiving' andi discharging ends, coupling? means l'alitlthef fuelr'eceiving" end of said conduit for" connecting thelatter to"a source of fuel, ynozzle means conne'ctedfto the fuel-discharging end; a lsleevesurrounding said conduit andin bearing'contact therewith to permit rotatively Y.'ang'ulariladjustment ofsaid conduit therein, supporting means for positioning said assembly within; 'said "du'ct, said supporting means iixedly engaging' said sleeve to prevent'rotativelyangular movement of the latterv with such movement of said" conduit, and ignition means so carried-'operatively adjacent said nozzle means bylsaid' supportingV meansas to prevent saidignition means from participating .in said 'angular-adjustment.; d d

vr2.1A firing head assembly for fuel burners of thef'gun 'type having al tubular air blast vduct adapted for connection to al blower, said assembly being adapted and arranged to be positioned substantially" aidally in said Jduct and 'comprising a fuel lconduit having fuel-receiving and -`discharging endsya spray; nozzle assembly secured to the discharge end of saidiconduit, air deflecting meanssurroundinggsaid'nozzle assembly in concentrically spaced relationithereto, a sleeve surrounding said-oonduit andin bearing contact therewith; `to permit rotatively angular adjustmentofthe utter therena yokesecured to said sleeve, said yoke. beingsupported from said deiiector means- Wherebysaid sleeve-is positioned substantially axially offsaid duct, and ignition means carried partly by said yoke and partly by said air deflecting means, said conduit being freev of saidyyoke to j perrnitA rotatively angular adjustmentof said 'conduit within said sleeve independently of-said-yoke and air deiiector means. l 3..Aring-head assembly-for fuel burners of the ygunetype havingatubular air blast duct adapted for connection to a blower, said assembly being adapted and arranged to be positioned substantially axially in said duct and comprising a fuel conduit having fuel-receiving and discharging ends, a spray nozzle assembly secured to the discharge end of said conduit, air deiiecting means surrounding said nozzle assembly in concentrically spaced relation thereto, a sleeve surrounding said conduit and in bearing contact therewith to permit rotatively angular adjustment of the latter therein, a yoke secured to said sleeve and a bridging member supporting said yoke and sleeve from said air deflector means, and ignition means carried partly by said yoke and partly by said air deflecting means, said conduit being free of said yoke to permit rotatively angular adjustment of said conduit within said sleeve independently of said yoke and air deflector means.

4. A fuel burner of the gun type having an air duct including a blower housing and a blast tube leading from said housing, a firing head assembly in said duct, said assembly including a fuel conduit which extends from a point adjacent the outlet end of said blast tube through the said blower housing to a point outside the latter, said conduit having at its rear or fuel-receiving end a coupling for connecting said conduit to a source of fuel supply, a spray nozzle assembly at the forward end of said conduit, a sleeve surrounding said conduit and in bearing contact therewith to permit rotatively angular adjustment of said conduit therein, said sleeve also extending through the wall of the blower housing, supporting means adjacent the forward end of said Asleeve 'and-ins :orltact with'. the; inner; Wall of. said blast-tube,Y said; means fixedly enea-eine said sleeve to positioni it substantially axially of said blast tube, and; ignitiony means so carried operatively adjacent the nozzle by said supporting means as to prevent said ignition means from participating in said angular adjustment.

5. A fuel burner as defined in claim 4, wherein said sleeve is providedwhere it passes through the blower housing wall, with means, adapted and arranged to engage saidwall for preventing rotatively angular movement of said sleeve.

6, A firing head assembly for fuel burners of the gun type havingv a tubular air blast duct adapted for connection to a blower, said assembly beine adapted. and arranged to be positioned Within said duct substantially axially thereof and comprising a` fuel conduit-having `fuel-receiving and discharging ends, said conduit being of sufiicient length to cause its fuel-receiving end to project rearwardly' outside said duct when said firing head assembly is properly positioned therein, a flared-tubecouplingv nipple at the fuel-receiving end of said conduit, the latter being adapted to receive a flared tube and gland nut for connecting said conduit toga fuel supply pipe, a spray nozzle assembly at the discharge end of said conduit, a sleeve surrounding said conduit and in bearing contact therewith to permit rotatively angular adjustment of the latter therein, and a supporting member receiving and xedly engaging said sleeve to prevent said sleeve from participating in the adjusting movement of said conduit.

7. A firingr head assembly for fuel burners as defined in claim 6, wherein said sleeve extends the full distance between said coupling and said nozzle assembly so as to bein endwise abutment with each, whereby longitudinal movement of -sa-cl- ,conduit with. respect to: sadi sleeve is prevented.

8-Ajring. head assembly for fuel burners of the gun` type vhaving an air duct including a blower rhousing anda blast tube leading from said housing, air deiiector means stationarily mounted within and engaging the inner periphery of said tube adjacent its nozzle end and having a hub portion extending axially of said tube, and ignition means mounted on said deector means operatively adjacent the nozzle end of said tube;` which firing head assembly comprises nozzle meansV adapted and arranged to be positionedv within said h ub portion with freedom for rotative angular adjustment, a sleeve adapted and arranged to be secured thereto and to extendA rearwardly therefrom axially of said tube and project through an aperture in a wall of the blower housing, a fuel conduit fitting loosely withinsaid sleeve and projecting rearwardly therefrom, and having provision for rigid connection to said spray nozzle whereby angular turning movementfof Vsaid fuel conduit within its sleeve Will impart corresponding angular movement of .said nozzle, and provision at the rearwardly projecting end of said fuel conduit for coupling the same to a fuel supply.

RALPH W. DE LANCEY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,887,150 Forney Nov. 8, 1932 2,222,031 Hammer Nov. 19, 1940 2,538,460 Kaveny 1 Jan. 16, 1951 FOREIGN PATENTS Number Country Date 171,513 Germany Aug. 31, 1934 

